One of the most common and versatile methods of building construction employs concrete masonry. Concrete masonry units (C.M.U.) are manufactured in various sizes, shapes, colors, and surface finishes for use in a wide variety of applications. The most common C.M.U. shapes include standard (or stretcher) units, open-ended (including bond beam, lintel, and knock-out) units, as well as single and double open-end units. The C.M.U.'s come in a number of relatively standard dimensions. Typical sizes and shapes of C.M.U.'s are illustrated in National Concrete Masonry Association (NCMA) Technical Bulletin No. TEK 2-1A (1995), the disclosure of which is incorporated herein by reference.
Other types of units besides C.M.U.'s are also commonly employed in constructing unit masonry wall systems. These include bricks (and other clay or shale units), structural tile, glass units, stone, and pre-cast stone. As used hereinafter, "unit", "masonry unit," or "block" is intended to include any construction unit utilized in building unit masonry wall systems including those units described above.
Different sized, shaped and types of masonry units are often utilized in combination. The units are typically laid up with mortar and, optionally, with steel reinforcement, grout, and other accessories to form unit masonry wall systems of enumerable variety in size and shape. The units each often have one or more vertically extending interior cavities hereinafter referred to as "cores" so that, when multiple courses of the blocks are assembled to form a wall, the cores of the blocks are aligned to form unobstructed, continuous series of vertical spaces within the wall. Basic unit masonry wall system designs include single wythe, multiple wythe (such as cavity wall systems), and veneer systems.
A persistent problem in the design and construction of concrete unit masonry wall systems is the migration of water from the exterior of the block walls to the interior of the building. Designers and builders have tried various methods and apparatus to intercept the flow of water through masonry, direct it to the exterior of the structure, and to prevent the upward migration of water from below grade level. One accepted approach is to install flashing at any location in block walls where the potential exists for water penetration, such as the top of walls at copings, at the base of parapets, over openings, beneath sills, over bond beams, at shelf angles, at the tops of foundations, and in walls at ground level to serve as a water stop. The installation of flashing is, however, labor intensive, and therefore costly. In particular, conventional flashing is difficult and time consuming to properly install in block courses including rebar or other vertical reinforcement. Moreover, conventional flashing has limited effectiveness in single wythe wall systems since the flashing cannot be installed to slope toward the weep holes in the blocks. In addition, conventional flashing is difficult to inspect since, once installed, flashing may not be evident from the exterior of the wall.
U.S. Pat. No. 5,115,614, issued to McGrath, discloses an integral flashing unit comprising a custom designed masonry block which includes a solid base and integral weep slot for collecting and directing water from the interior cavities of blocks installed in courses above the flashing unit and directing the water to the exterior of the wall. One drawback of the above-mentioned system is that it requires fabrication and shipment of a separate set of non-standard blocks for each construction job. Moreover, the nationwide acceptance and use of such specialty units is inhibited by the high costs of shipping the custom-made blocks.
U.S. Pat. No. 4,910,931, issued to Pardue, Jr., discloses a water collection and drainage system which includes a system of upper water collection pans suitable for installation in upper bond beam courses, which pans collect and direct the water through the vertical block cavities and lower block courses to another series of collection pans at a lower beam block course, which in turn direct the water to base collection pans at the lower most beam block course where the water is directed to the exterior of the wall through weeping spouts. Drawbacks to this system include the cost and complexity of installation of the multiple tiers of collection pans, as well as design limitations in the system which require installation solely in bond beam courses.
An object of the present invention, therefore, is to provide an effective drainage system for unit masonry wall systems which can be fabricated, shipped to construction sites, and installed at a low cost.
Another object of the present invention is to provide a drainage system for unit masonry wall systems which can be installed in any of a variety of standard masonry block units, including bond beam units, knock-out units, and standard two-core and three-core units.
Another object of the present invention is to provide a drainage system including water collection pans which can be quickly installed in any of a variety of standard masonry units to implement a drainage system for single wythe or cavity wall systems, as well as for masonry veneer systems.
Yet another object of the present invention is to provide water collection pans which may be quickly and easily installed at various locations in unit masonry wall systems to effect drainage of collected water to the exterior of the walls.
Another object of the present invention is to provide a drainage system including water collection pans which can be installed and utilized below grade to provide effective collection and diversion (to either the interior or the exterior) from basement walls.
Another object of the present invention is to provide a drainage system including water collection pans which can be installed to provide effective collection and diversion (to one side or the other, as desired) from retaining walls.
It is yet another object of the present invention to provide water collection pans which are nestable for compact packing to reduce storage volumes and shipping costs.
In carrying out the above and other objects, the drainage system of the present invention includes a plurality of water collection pans which may be quickly inserted in the interior cavities of each of the blocks over the length of a selected block wall course for collecting water drained through the cores of the upper courses and directing the water to the exterior of the block wall through an adjacent head joint or bed joint, depending on the type of block.
One embodiment of the collection pans utilized in the system for blocks (such as bond beam, lintel, or knock-out blocks) wherein the blocks include an interior cavity and the endwalls (or ends) of the block are open at the upper portion thereof, the pan includes the collector portion for positioning in the interior cavity of the block and extending across substantially the entire length of the interior cavity, the front and rear edges of the collector portion each including a flange extending generally horizontally to contact the top surface of the block adjacent the interior cavity, and a drainage channel extending outward from the collector portion past the endwall of the block into the head joint between the block and an adjacent block.
Another embodiment of the water collection pan designed for use with standard masonry units having one or more vertically extending cores bounded by endwalls which extend to the top surface of the block includes a collector portion for positioning in the core of the block, each of the front and rear edges including a flange extending generally horizontally from the edge to contact the top surface of the block adjacent the core, and a drainage channel extending downward from an opening in the collector portion through the core toward the front wall of the block and extending below the block so that the end of the drainage channel may be positioned in the bed joint below the block.
The water collection pans may be fabricated from any water impervious, corrosion resistant construction material, such as molded plastic, sheet metal, or other corrosion resistant water impervious material suitable for inexpensive mass production, as well as effective water collection and diversion in unit masonry wall systems.
The water collection pans are also preferably designed so that they can be inexpensively molded and, wherever possible, nestable with each other for compact storage and shipment.
These and other objects, features, and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings.